Explanation Chemical equation is as follows: C 5 H 5 N ( a q ) + H C l ( a q ) → C 5 H 5 N H C l ( a q ) Concentration of C 5 H 5 N ( M 1 ) = 0.125 M Volume of C 5 H 5 N ( V 1 ) = 25 m L Concentration of H C l ( M 2 ) = 0.100 M Initial p H : C 5 H 5 N ( a q ) + H 2 O ( l ) ⇌ C 5 H 5 N H + ( a q ) + O H − ( a q ) I ( M ) 0.125 0 0 C ( M ) − x + x + x E ( M ) 0.125 − x x x K b = [ C 5 H 5 N H + ] [ O H − ] [ C 5 H 5 N ] = ( x ) ( x ) ( 0.125 − x ) 1.7 × 10 − 9 = ( x ) ( x ) ( 0.125 − x ) ( 0.125 − x ) ≈ 0.125 x = 1.7 × 10 − 9 × 0.125 = 1.46 × 10 − 5 On solving the above equation, we get x = 1.46 × 10 − 5 = [ O H − ] . [ H 3 O + ] = K w [ O H − ] = 1.0 × 10 − 14 1.46 × 10 − 5 = 6.9 × 10 − 10 M p H = − log [ H 3 O + ] = − log ( 6.9 × 10 − 10 ) = 9.16 10 mL of acid added: C 5 H 5 N ( a q ) + H C l ( a q ) → C 5 H 5 N H C l ( a q ) B e f o r e r x n 0.125 M × 0.025 L 0.100 M × 0.010 L ( m o l e s ) = 0.003125 = 0.001 A f t e r r x n 0.002125 0 0 0.001 ( m o l e s ) p H = p K a + log [ b a s e ] [ a c i d ] p K b f o r p y r i d i n e i s 8.7. B u t p K b + p K a = 14 p K a = 14 − 8.7 = 5.3 Here concentration is replaced by number of moles as the volume of base and acid is same. Hence, p H = 5.3 + log 0.002125 0.001 = 5.62 20 mL of acid added: C 5 H 5 N ( a q ) + H C l ( a q ) → C 5 H 5 N H C l ( a q ) B e f o r e r x n 0.125 M × 0.025 L 0.100 M × 0.020 L ( m o l e s ) = 0.003125 = 0.002 A f t e r r x n 0.001125 0 0.002 ( m o l e s ) Formula: p H = p K a + log [ a c i d ] [ b a s e ] p K b for pyridine is 8.7. But p K b + p K a = 14 Hence, p K a = 5.3 . Here concentration is replaced by a number of moles as the volume of base and acid is same. p H = 5.3 + log 0.001125 0.002 = 5.05 pH at one-half of the equivalence point: At this point, [ b a s e ] = [ a c i d ] . Thus, p H = p K a . = 5.3 pH at the equivalence point: [ C 5 H 5 N H + ] = 0

Mastering Chemistry with Pearson eText -- Standalone Access Card -- for Chemistry: A Molecular Approach (4th Edition)

4th Edition

ISBN: 9780134162485

Author: Nivaldo J. Tro

Publisher: PEARSON

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Acid Base Titration

An acid-base titration is the method of quantitative analysis for determining the concentration of an acid and base by exactly neutralizing it with a standard solution of base or acid having known concentration.

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Chapter 17, Problem 74E

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Interpretation: For the titration of a 25.0-mL sample of 0.125 M pyridine with 1.00 M HCl, the pH at each volume of added base: 0 mL, 5 mL, 10 mL, equivalence point, one-half equivalence point, 20 mL, 25 mL are to be determined. Along with this, the titration curve is to be sketched.

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Chapter 17, Problem 73E

Chapter 17, Problem 75E

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Mastering Chemistry with Pearson eText -- Standalone Access Card -- for Chemistry: A Molecular Approach (4th Edition)

Ch. 17 - Prob. 1SAQ Ch. 17 - Q2. What is the pH of a buffer that is 0.120 M in...Ch. 17 - Q3. A buffer with a pH of 9.85 contains CH3NH2 and...Ch. 17 - Q4. A 500.0-mL buffer solution is 0.10 M in...Ch. 17 - Q5. Consider a buffer composed of the weak acid HA...Ch. 17 - Q6. Which combination is the best choice to...Ch. 17 - Q7. A 25.0-mL sample of an unknown HBr solution is...Ch. 17 - Q8. A 10.0-mL sample of 0.200 M hydrocyanic acid...Ch. 17 - Q9. A 20.0-mL sample of 0.150 M ethylamine is...Ch. 17 - Q10. Three 15.0-mL acid samples—0.10 M HA, 0.10 M...

Ch. 17 - Q11. A weak unknown monoprotic acid is titrated...Ch. 17 - Q12. Calculate the molar solubility of lead(II)...Ch. 17 - Q13. Calculate the molar solubility of magnesium...Ch. 17 - Q14. A solution is 0.025 M in Pb2 +. What minimum...Ch. 17 - Q15. Which compound is more soluble in an acidic...Ch. 17 - 1. What is the pH range of human blood? How is...Ch. 17 - 2. What is a buffer? How does a buffer work? How...Ch. 17 - 3. What is the common ion effect? Ch. 17 - 4. What is the Henderson–Hasselbalch equation, and...Ch. 17 - 5. What is the pH of a buffer solution when the...Ch. 17 - 6. Suppose that a buffer contains equal amounts of...Ch. 17 - 7. How do you use the Henderson–Hasselbalch...Ch. 17 - 8. What factors influence the effectiveness of a...Ch. 17 - 9. What is the effective pH range of a buffer...Ch. 17 - 10. Describe acid–base titration. What is the...Ch. 17 - 11. The pH at the equivalence point of the...Ch. 17 - 12. The volume required to reach the equivalence...Ch. 17 - 13. In the titration of a strong acid with a...Ch. 17 - 14. In the titration of a weak acid with a strong...Ch. 17 - 15. The titration of a polyprotic acid with...Ch. 17 - 16. In the titration of a polyprotic acid, the...Ch. 17 - 17. What is the difference between the endpoint...Ch. 17 - 18. What is an indicator? How can an indicator...Ch. 17 - 19. What is the solubility product constant? Write...Ch. 17 - 20. What is molar solubility? How can you obtain...Ch. 17 - 21. How does a common ion affect the solubility of...Ch. 17 - 22. How is the solubility of an ionic compound...Ch. 17 - 23. For a given solution containing an ionic...Ch. 17 - 24. What is selective precipitation? Under which...Ch. 17 - 25. What is qualitative analysis? How does...Ch. 17 - 26. What are the main groups in the general...Ch. 17 - 27. In which of these solutions will HNO2 ionize...Ch. 17 - 28. A formic acid solution has a pH of 3.25. Which...Ch. 17 - 29. Solve an equilibrium problem (using an ICE...Ch. 17 - 30. Solve an equilibrium problem (using an ICE...Ch. 17 - 31. Calculate the percent ionization of a 0.15 M...Ch. 17 - 32. Calculate the percent ionization of a 0.13 M...Ch. 17 - 33. Solve an equilibrium problem (using an ICE...Ch. 17 - 34. Solve an equilibrium problem (using an ICE...Ch. 17 - 35. A buffer contains significant amounts of...Ch. 17 - 36. A buffer contains significant amounts of...Ch. 17 - Prob. 37E Ch. 17 - Prob. 38E Ch. 17 - 39. Use the Henderson–Hasselbalch equation to...Ch. 17 - 40. Use the Henderson–Hasselbalch equation to...Ch. 17 - 41. Calculate the pH of the solution that results...Ch. 17 - 42. Calculate the pH of the solution that results...Ch. 17 - 43. Calculate the ratio of NaF to HF required to...Ch. 17 - 44. Calculate the ratio of CH3NH2 to CH3NH3Cl...Ch. 17 - Prob. 45E Ch. 17 - 46. What mass of ammonium chloride should you add...Ch. 17 - 47. A 250.0-mL buffer solution is 0.250 M in...Ch. 17 - 48. A 100.0-mL buffer solution is 0.175 M in HClO...Ch. 17 - Prob. 49E Ch. 17 - 50. For each solution, calculate the initial and...Ch. 17 - Prob. 51E Ch. 17 - 52. A 100.0-mL buffer solution is 0.100 M in NH3...Ch. 17 - 53. Determine whether or not the mixing of each...Ch. 17 - 54. Determine whether or not the mixing of each...Ch. 17 - 55. Blood is buffered by carbonic acid and the...Ch. 17 - 56. The fluids within cells are buffered by H2PO4–...Ch. 17 - 57. Which buffer system is the best choice to...Ch. 17 - Prob. 58E Ch. 17 - 59. A 500.0-mL buffer solution is 0.100 M in HNO2...Ch. 17 - Prob. 60E Ch. 17 - Prob. 61E Ch. 17 - 62. Two 25.0-mL samples, one 0.100 M HCl and the...Ch. 17 - 63. Two 20.0-mL samples, one 0.200 M KOH and the...Ch. 17 - 64. The graphs labeled (a) and (b) show the...Ch. 17 - 65. Consider the curve shown here for the...Ch. 17 - 66. Consider the curve shown here for the...Ch. 17 - 67. Consider the titration of a 35.0-mL sample of...Ch. 17 - Prob. 68E Ch. 17 - 69. Consider the titration of a 25.0-mL sample of...Ch. 17 - Prob. 70E Ch. 17 - 71. Consider the titration of a 20.0-mL sample of...Ch. 17 - Prob. 72E Ch. 17 - Prob. 73E Ch. 17 - Prob. 74E Ch. 17 - Prob. 75E Ch. 17 - Prob. 76E Ch. 17 - Prob. 77E Ch. 17 - 78. A 0.446-g sample of an unknown monoprotic acid...Ch. 17 - Prob. 79E Ch. 17 - Prob. 80E Ch. 17 - Prob. 81E Ch. 17 - Prob. 82E Ch. 17 - Prob. 83E Ch. 17 - 84. Referring to Table 17.1, pick an indicator for...Ch. 17 - Prob. 85E Ch. 17 - Prob. 86E Ch. 17 - 87. Refer to the Ksp values in Table 17.2 to...Ch. 17 - 88. Refer to the Ksp values in Table 17.2 to...Ch. 17 - 89. Use the given molar solubilities in pure water...Ch. 17 - Prob. 90E Ch. 17 - Prob. 91E Ch. 17 - Prob. 92E Ch. 17 - 93. Refer to the Ksp value from Table 17.2 to...Ch. 17 - Prob. 94E Ch. 17 - 95. Calculate the molar solubility of barium...Ch. 17 - Prob. 96E Ch. 17 - Prob. 97E Ch. 17 - Prob. 98E Ch. 17 - Prob. 99E Ch. 17 - Prob. 100E Ch. 17 - Prob. 101E Ch. 17 - Prob. 102E Ch. 17 - Prob. 103E Ch. 17 - Prob. 104E Ch. 17 - Prob. 105E Ch. 17 - Prob. 106E Ch. 17 - Prob. 107E Ch. 17 - Prob. 108E Ch. 17 - Prob. 109E Ch. 17 - Prob. 110E Ch. 17 - Prob. 111E Ch. 17 - Prob. 112E Ch. 17 - 113. A 150.0-mL solution contains 2.05 g of sodium...Ch. 17 - Prob. 114E Ch. 17 - Prob. 115E Ch. 17 - Prob. 116E Ch. 17 - Prob. 117E Ch. 17 - 118. A 250.0-mL buffer solution initially contains...Ch. 17 - 119. In analytical chemistry, bases used for...Ch. 17 - Prob. 120E Ch. 17 - Prob. 121E Ch. 17 - Prob. 122E Ch. 17 - Prob. 123E Ch. 17 - Prob. 124E Ch. 17 - Prob. 125E Ch. 17 - Prob. 126E Ch. 17 - Prob. 127E Ch. 17 - Prob. 128E Ch. 17 - Prob. 129E Ch. 17 - Prob. 130E Ch. 17 - 131. The Kb of hydroxylamine, NH2OH, is 1.10 ×...Ch. 17 - 132. A 0.867-g sample of an unknown acid requires...Ch. 17 - Prob. 133E Ch. 17 - Prob. 134E Ch. 17 - 135. What relative masses of dimethyl amine and...Ch. 17 - Prob. 136E Ch. 17 - Prob. 137E Ch. 17 - Prob. 138E Ch. 17 - 139. Since soap and detergent action is hindered...Ch. 17 - 140. A 0.558-g sample of a diprotic acid with a...Ch. 17 - 141. When excess solid Mg(OH)2 is shaken with 1.00...Ch. 17 - Prob. 142E Ch. 17 - Prob. 143E Ch. 17 - Prob. 144E Ch. 17 - Prob. 145E Ch. 17 - Prob. 146E Ch. 17 - Prob. 147E Ch. 17 - 148. What amount of HCl gas must be added to 1.00...Ch. 17 - 149. Without doing any calculations, determine if...Ch. 17 - 150. A buffer contains 0.10 mol of a weak acid and...Ch. 17 - Prob. 151E Ch. 17 - Prob. 152E Ch. 17 - Prob. 153E Ch. 17 - Prob. 154E Ch. 17 - Prob. 155QGW Ch. 17 - Prob. 156QGW Ch. 17 - Prob. 157QGW Ch. 17 - 158. A certain town gets its water from an...Ch. 17 - Prob. 159QGW Ch. 17 - Buffers and Hydroponics 160. Hydroponics is a...

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